Matthew,
As far I understood, you cannot create yet annotations with Annozilla.
Could you add a paragraph in your doc saying so in your project home
page and add a link from it to the Annotea project (like consult
this page if you want to see other clients, including clients that
can create annotations). Or, as an alternative, say that currently, you
can only create annotations with Amaya and Art's bookmarklet.
This way users will know how those annotations were made :)
Thanks,
-jose